Pump



May 10, 1938.

P. Gt MacGREGoR PUMP' Filed April 9, 1957 ATTORNEY! Patented May 1o, 1938 Y 2,116,684

UNITED STATES PATENT GFFICE PUlVIP Peter Graham MacGregor, Pequannock, N. J., as-

signor to Pyrene Manufacturing Company, Newark, N. J., a corporation of Delaware Application April 9, 1937, Serial No. 135,827

1 Claim. (C1. 10S-192) This invention relates to pumps and has parand I8, respectively, through the former of which ticular reference to iire extinguisher pumps of liquid is delivered to the piston tube on the inthe double-acting type. ward stroke of that tube and through the latter An important object of the present invention of which liquid is delivered to the piston tube on 5 is to provide a generally improved fire extinthe outward stroke of that tube. On the inner 5 guisher pump; and to that end the invention conend of the piston tube I4, there is slidably cartemplates a simple and reliable means, whereby ried a piston 20, which is adapted to so move pressure set up within the pump tube or cylinder with relation to the piston tube on its inward incident to the discharge of liquid therefrom may stroke as to open the discharge ports I'I and close be utilized to attain an effective seal between the the discharge ports I8 and which is adapted to 10 pump piston and the inner wall of the pump tube so move with relation to the piston tube on its or cylinder. outward stroke as to open. the discharge ports Other objects and advantages of the invention I8 and close the discharge ports I1. The piston will become apparent from the following descrip- 2'0 is limited in its movement in one direction on tion of the invention when taken in connection the piston tube by a Sleeve 2l carried by that 15 with the accompanying drawing, in. whichtube adjacent the ports I8 and is limited in its I Fig. l is a view partly in section and partly mOVEment 0n 0110 IJSOD tub@ in all ODDOSG din elevation of a re extinguisher embodying the rection by a gland nut 22 carried at the end of present invention; that tube and provided with a packing 23 which Fig. 2 is a transverse sectional view taken on surrounds the nozzle tube I5. 20 line 2-2 of Fig. l; The piston 2B is formed from a suitable mate- Fig. 3 is a perspective view of the pump piston; rial, such as Bakelite, and is provided on its outer Fig. 4 is a perspective view of a piston ring surface with an annular channel 24, from the adapted for use with the pump piston; bottom of which a plurality of pressure ducts 25 25 Fig. 5 is an enlarged view partly in section. and lead to the central opening of the piston within 25 partly in elevation showing the position of the which the piston tube I4 is slidably accommopiston with reference to the piston tube on its dated. The pressure ducts are preferably three inward stroke; and in number and are equidistantly spaced from Fig. 6 is a view similar to that of Fig. 5 and each other so that at least one of, them will com- 3o showing the position of the piston on the piston municate with the piston tube I4 by way of one 30 tube on its outward stroke. or the other of the discharge ports I8 on the The extinguisher herein shown as embodying inward stroke of the piston tube; and so that at the present invention includes a liquid recepleast one of them will communicate with the pistacle I0, within which is arranged a pump II of ton tube by way of one or the other of the disthe double-acting type, such as is shown and decharge ports I'I on the outward stroke of the 35 scribed in United States Patent No. 1,688,195, piston tube. Within the annular channel 24, granted to Peter G. MacGregor, October 16, there is carried an expansiblepiston ring 26, the 1928, from which it will be understood that the width oi which is such that it snugly engages the pump is adapted to rotate about its longitudinal side walls of the channel. The piston ring 26 is axis and is equipped with suitable liquid pick-up preferably constructed of Celluloid and is adapted 40 means by which proper ingress of liquid to the to be expanded radially outwardly under the inpump is insured regardless of the position in uence of pressure transmitted to the annular which the extinguisher is held while being operchannel 24 from the piston tube I4 by way of one ated. or the other of the discharge ports I1 and at least The pump II includes a pump tube I2, within one of the pressure ducts 25 on the inward stroke 45 which is arranged a piston tube I4, adapted for of the piston tube, and to be similarly expanded reciprocation with respect to the pump tube and under the inuence of pressure transmitted to also with respect to a nozzle tube I5 disposed the annular channel from the piston tube by way centrally of the piston tube and through which of one or the other of the discharge ports I'I and liquid is discharged by way of its upper or inlet at least one of the pressure ducts 25 on the out- 50 end, the nozzle tube being secured in position by ward stroke of the piston tube. reason of its connection with a nozzle tip I6 which Regarding the operation of the fire extinguishis attached to the outlet end of the liquid receper, it will be understood that as the piston tube tacle IIJ. The piston tube I4 is provided at its I4 is moved inwardly (downwardly in the drawinner end with two pairs of discharge ports I1 ing) liquid is drawn into the upper end of the 55 pump tube l2, as viewed in Figs. 1, 5 and 6, and that liquid contained in the lower end of the pump tube l2 is discharged therefrom by Way of the discharge ports Il, the piston tube I4 and the nozzle tube I5; whereas on the outward (upward) stroke of the piston tube lli, liquid is drawn into the lower end of the pump I2 and liquid contained in the upper end of the p-ump tube is discharged therefrom byway of the discharge ports i8, the piston tube M and the nozzle tube I5.

As the pump is operated the piston 2U serves as a valve, one function of which is to establish communication between the piston tube M and that end of the pump tube i 2 which becomes the high-pressure end of such tube incident to initiating either an outward or inward strdke of the piston tube, and another function of which is to sever communication between the piston tube and the low-pressure endof the pump. Moreover, the piston functions as a valve to' establish communication between the annular channel 2d and the alternate high-pressure ends of the pump tube, so as to insure delivery of fluid pressure to Vthat channel.

Inasmuch as the fluid pressure which is delivered to the annular channel 2d from the alternate high-pressure ends of the pump tube l2 acts on the expansible piston ring 2B to force or expand it radially outwardly into rm contact with the inner wall of the pump tube i2, it follows that the escape of liquid from the high-pressure side of the pump tube to the low-pressure side thereof by way of the periphery off the piston ring is effectively prevented. It will be observed also that escape of liquid from the high-pressure side 'of the pump tube i2 to the low-pressure side thereof by way of the annular channel 24 is eiectively prevented, because the piston ring 26 snugly engages the side wall of that channel.

Although only one fovrm of the invention is herein shown and described, it will be understood that various changes may be made without departing from the spirit of the invention or the scope of the following claim.

What is claimed is:

In a pump of the double-acting type, a tubular piston rod, the passage in which serves as a discharge conduit' andl the wall of `which is provided with a pair of spaced ports, one of which is adapted to serve as a discharge port for one end of the pump and the other of which is adapted to serve as a discharge port for the other end of the pump, a piston having an opening therein through which said piston rod has a limited sliding movement, said piston v having an annular channel formed on its outer surface and provided with a pressure duct leading from the bottom of said channel to the opening through said piston, the range of movement of the piston on the piston rod and the spacebetween the discharge ports being so proportioned with respect to the location of the pressure duct in the piston that said duct is adaptedt communicate with said discharge conduit by Way of one of said discharge ports when the piston is at either limit of its range of movement, said piston functioning as a valve adapted to close one of said ports and open the other incident to movement of said piston rod in one direction and to close said other port and Open said one port incident to movement of said piston rod in an opposite direction, and an eXpansible piston ring carried Within said channel and adapted to be expanded radially outwardly under the influence of pressure transmitted from said discharge conduit by way of said pressure duct and one or the other of said discharge ports incident to reciprocation of said piston.

PETER GRAHAM MACGREGOR. 

